Sweetening hydrocarbon oils



, 10 also come in contact with copper and other metals droXide (NaOI-I) The amounts of sodium hypo- 65 40 tion can b di d d after process is replacing the sweetening process here- 95 n "i' P g MM MW-rum..-

r Fr es SWEETENING HYDROCARBON OILS Richard S. 'McClaughry and Louis V. Moore, Hammond, Ind, 'assignors to Standard Oil Company (Ind), Chicago, 111., a corporation of Indiana N Drawing. Application February 13, 1920 Serial No. 428,236

4 @laims. (Cl. 196-33) This invention relates to a method of sweetdrawn off, and the naphtha is washed three or ening hydrocarbon oils and it pertains more parfour times with water to remove traces of doctor ticularly to the treatment of naphtha for use by solution, since lead compounds remaining in the paint and varnish manufacturers. oil are undesirable in the subsequent steps of the 5 The naphtha thinner used in paints and varprocess. I 0 nishes must be sweetened to a higher degree The naphtha is then treated with from to than most hydrocarbon oils because it is used 150 barrels of a dilute solution of sodium hypoin combination with heavy metal soap driers chlorite (NaOCl) containing about 0.2% of availwhich form black sulfides. Paints and varnishes able chlorine and about 0.2% excess sodium hywhich are tarnished by small amounts of sulfur. chlorite solution required will depend upon the The oflicial sulfur test for gasoline adopted by amount of sulfur impurities in the naphtha, and the American Society of Testing Materials, should be adjusted so that at the end of the which is often used as a sulfur test for'naphtha, treatment, the hypo is Practically p 15 is to immerse a copper strip in the naphtha at With distillate from Mid-Continent crude, we 122 r. for three hours. The Perdcw'test is to have f und that an a unt f hyp h rit s lusubject mercury to the naphtha, making use tion containing about 140 pounds of chlorine is of the afiinity of mercaptans for this metal. Rerequired in the treatment of the batch herein cently, a more rigid test has been adopted, described. After the hypochlorite treatment the 20 namely, th fl Pe t, t st i hich a bri ht oil must be thoroughly washed with water to copper strip is heated in naphtha at about remove EXCESS yp t 350 F. for one-half hour. Naphthas which meet It would be difficult if not impossible to state all th fermer t t 1 t always t th rigorous of the reactions that characterize this treatment. du Pont test, and neither the doctor nor the It appears, however, that .doctor solution re- 25 hypcchlorite sweetening process heretofore used moves sulfur in the prese c of excess apwill give a product that will pass the du Pont tans and not in the absence thereof. The first test. The object of our invention is to provide Step, therefore, eliminates the Sulfur and y a sweetening process for naphtha by which it eave ad m p s in Solution The yI can be made to meet the most rigorous requirechlorite treatment, while ineffective in removing 80 ments of paint and varnish manufacturers. sulfur, ppa t y converts the d. m captides Other objects will be apparent as the detailed into harmless P All y e e 00mdescription of our invention proceeds. bined treatment yields a sweet stable product Briefly we contemplate a combination sweetthat easily ts e d Pont test. I ening process, wherein a treatment with doctor We do not rely 39 any 611901195 xp ain solution is followed, after complete washing, by y the Combination of treatments set forth a special hypochlorite t t t, th hypo will effect a sweetening which cannot be effected chlorite solution containing about 0.2% of availby either DTOQESS pp y lf. The success able chlorine, and being used in amounts so that Of the combined D w b en the chlorine is practically used up and t 1 demonstrated on a commercial scale and this new To describe our invention in detail, we begin tofore usedwithahydrocarbon oil, preferablyasour naphtha While We have described in detail a p with a boiling range of 350 to 472 F. A 1,600 ferred embodiment of our invention, we do not barrel batch of the sour naphtha is first treated limit Ourselves to any of such details exc pt as with about 75 barrels of sodium plumbite, prefdefined y th pp a Ch10ride Of erably a solution containing 2-l% available lead. lime other hypochlolite y be u ed i stead Thi i th reagent commonly referred t of the sodium hypochlorite, various concentradoctor solution, and is prepared by dissolving tions of both hypochlorite and doctor solutions r lead oxide in sodium hydroxide in a manner well may be used, and other modifications may be known in this art. In our process the doctor employed to suit the process to any particular solution should be free from elemental sulfur and refinery.

preferably should contain no bottom settling or We claim:

precipitated lead sulfide. 1. The method of sweetening petroleum hy- 55 After thoroughly mixing the naphtha with the drocarbon naphtha so that it gives a negative test doctor solution, the doctor solution is settled and for sulfur when contacted with a polished copper 110 strip at 350 F. for thirty minutes, which comprises treating said naphtha with doctor solution in the absence of free sulfur, giving the treated naphtha a plurality of water washes and treating the naphtha with an alkaline hypochlorite v: naphtha, and treating said naphtha with an alkaline hypochlorite solution.

3. The method of sweetening sour petroleum naphtha that boils within the range of 350 to 4'! 2 F. for use in paint and varnish compositions so that said naphtha gives a negative test for sulfur when contacted with a polished copper strip at 350 F. for thirty minutes which com- I as;

prises treating said naphtha with a solution of sodium plumbite in the absence of free sulfur, giving the treated naphtha a plurality of water washes, treating the naphtha with sodiumhypochlorite, and then washing the naph ha with water to remove the excess sodium hypochlorite. 4. The method of sweetening sour petroleum naphtha that boils within the range of 350' to 472 F. for use in paint and varnish compositions so that said naphtha gives a negative test for sulfur when contacted with a polished copper strip at 350 F. for thirty minutes, which comprises treating said sour naphtha with doctor solution in the absence of free sulfur, thoroughly washing out traces of the doctor solution, then treating said naphtha with an alkaline hypochlorite solution containing about 0.2% of available chlcrine and then thoroughly washing the treated naphtha with water to remove excess hypochlorite solution.

RICHARD S. MCCLAUGI-IRY. LOUIS V. MOORE. 

